问题
选择题
Mary often studies English by _______ with a group.
A．working
B．work
C．to work
D．worked
答案
答案：A
因为by为介词，后接动词ing 形式，故选A
搜题请搜索小程序“爱下问搜题”
Mary often studies English by _______ with a group.
A．working
B．work
C．to work
D．worked
答案：A
因为by为介词，后接动词ing 形式，故选A